Method of converting waste filamentary material into staple fiber



Feb. 25, 1969 N. ROSENSTEIN ET AL 3,429,018

METHOD OF CONVERTING WASTE FILAMENTARY MATERIAL INTO STAPLE FIBER Filed March 9, 1967 Shet of 2 INVEN'I'ORS. NATHAN ROSENSTEIN ABRAHAM J. ROSENSTEIN ATTORNEYS.

Feb. 25, 1969 N. ROSENSTEIN ET AL 3,429,018

METHOD OF CONVERTING WASTE FILAMENTARY MATERIAL INTO STAPLE FIBER Filed March 9, 1967 Sheet 2 of 2 INVENTOR. NATHAN ROSENSTEIN Y ABRAHAM J. ROSENSTEIN ATTORNEYS,

United States Patent Of 3 Claims ABSTRACT OF THE DISCLOSURE A plurality of supply packages of Waste synthetic filamentary material containing knots. excessive twist, excessive finish etc. are creeled and the ends of such packages are fed in the form of a web of spaced ends between counter-rotating rollers. The rollers are pressure loaded sufficiently to substantially destroy the knots and open the individual filaments. After passing the rollers the material is stuffer box crimped while still in web form and the crimps set. The resultant material is cut into staple lengths to produce a spinnable staple having three-dimensionally crimped fibers.

CROSS-REFERENCES TO RELATED APPLICATIONS This application is a continuation-in-part of our copending application Ser. No. 566,45 1, filed Mar. 2, 1966, now US. Patent No. 3,351,993, which application was a division of our US. application Ser. No. 57,070, filed Sept. 19,1960, now US. Patent No. 3,164,882.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to a staple fiber product, and to a process for producing a staple fiber product from waste filamentary material.

It is known that in the production of man-made continuous filament thermoplastic and thermosetting material by melt spinning and analogous methods, a substantial percentage of the filamentary product is never suitable for the end use originally intended for such product. This is due to mechanical and other failures which cause defects in the filamentary material such that it is not utilizable as a commercial product and as a result must be downgraded into waste material. In this respect, the downgraded material accumulates essentially in two general manufacturing contexts, which are (1) the spinning area, and (2) the draw-Wind of draw-twist area. In the spinning area, either through mechanical failure of the basic spinning equipment, or uncontrolled changes in viscosity and other physical and chemical parameters, the result is that inferior undrawn filamentary material is accumulated in undrawn tangled form in undrawn form on bobbins pend ing correction of the failure. In the drawn-Wind or drawtwist area, a percentage of filamentary material is spoiled prior to drawing mostly through the result of mechanical failures. Such spoiled material accumulates as Waste either by piling up after it is taken from the undrawn package, or, if the undrawn package becomes unsuitable for feeding to the draw-winder or draw-twister, the undrawn yarn is either cut from the package or segregated in package form. Subsequent to drawing or twisting, also through mechanical failure or error, the fully drawn filamentary material can pile up in tangled form, or the 3,429,018 Patented Feb. 25, 1969 drawn yarn can be wound, either with or without twist, on shipping pirns or bobbins which may have such defects therein as to make the material thereon unsuitable for subsequent efiicient fabrication. These defects include, without limitation, the following:

(a) Improper or inconsistent size due to failure in drawing.

(b) Excessive broken filaments.

(c) Excessive knots.

(d) Undersized packages due to necessity for early dofiing when mechanical failure occurs.

(e) Absence of transfer tails.

(f) Any other conditions which would make the continuous filament yarn unsuitable for eflicient and quality fabrication.

Wherever filamentary material accumulates in tangled form, either drawn or undrawn, there is no commercial alternative but to have such material used either (1) for regeneration melt spinning purposes in the manufacture of substandard nylon fiber or other nylon products, or (2) for garnetting purposes, where the more uniform garnets can be utilized in spinning woolen and worsted yarns, and the less suitable types of garnets may be used for fiber-fill, wadding, quilting, and the like.

Wherever inferior fully drawn downgraded filamentary material accumulates on bobbins, these bobbins are currently utilized essentially in two ways:

(a) Bobbin stripping: The drawn downgraded continuous filament material is either cut or air stripped from the bobbin or pirn and then sold to garnetters as tangled waste for garnetting purposes.

(b) Creeling and crimping: Some nylon producers and processors segregate downgraded continuous filamentary material on pirns or bobbins into material having essentially identical denier per filament. For example, taking a large bundle of downgraded continuous filament yarns such as 30/13; 60/20; 34, all of this material has a common 3 denier per filament basis. Likewise, a bundle of yarn such as /23; 200/34; and 840/ 140, all yield a common 6 denier per filament basis. By creeling such material having uniform deniers per filament into a large tow or bundle of continuous filaments, and by feeding the same into conventional tow crimping equipment, there is produced a bundle of crimped filaments which can subsequently be cut to required length for use as staple fiber in conventional wool and worsted spinning systems.

Inferior undrawn downgraded filamentary material must conventionally be first creeled, and then passed through draft rolls, and then fed into conventional tow crimping equipment as just described.

From the above, it will be obvious that the relatively high cost of bobbin stripping plus the high cost of cutting, garnetting, gilling, makes the bobbin stripping method of converting waste highly uneconomical and undesirable. Furthermore, the resultant product is poor and its market value low. As for the present creeling and crimping methods, the following factors limit the value thereof, and the resultant desirability of the staple fiber produced thereby for spinning purposes:

(a) All conventional stutter box crimpers for fiber crimping, by their very nature, crimp the fibers in one plane with the resultant crimped fiber being comparatively lean.

(b) Since most of the producer continuous filamentary material contains a small amount of producer twist, and spin finish, the conventional crimping equipment does not permit the individual filaments to separate. Therefore, subsequent additional processing or opening is necessary prior to spinning, particularly in the cotton system.

(c) "While methods have been devised for heat setting the crimped filaments processed through such conventional crimpers, it is diflicult to continuously crimp and heat set the material in a single process because of the conventional tow size of the filamentary product being fed to the crimper; moreover, conventional autoclave heat setting methods add substantially to the cost of the staple product.

((1) Present creeling and crimping methods fail to satisfactorily eliminate tangles and knots in the downgraded material.

Description of the prior art This invention relates generally to our U.S. Patent No. 2,715,309, and certain prior art references relating to distinct inventions are British 558,297; U.S. Patent No. 2,311,174; U.S. Patent No. 2,419,320; U.S. Patent No. 2,504,183, as well as the references cited in our earlier referred to related applications.

SUMMARY OF THE INVENTION It is therefore an object of this invention to produce a staple fiber product from downgraded waste filamentary material whereby the staple product when spun into yarn becomes a high bulk yarn suitable for fabrication.

It is a further object of this invention to provide a super-ior waste product that brings a maximum price in the fiber market.

Broadly, the process of this invention comprises (*1) segregating a plurality of creelable pirns of downgraded synthetic resin continuous multi-filamentary material into groups of pirns, pirns of said groups each having thereon material, the average denier per filament of the basic filaments thereof being substantially the same from pirn to pirn within each group, (2) passing a plurality of ends of such material from creelable pirns of a single group in a spaced apart parallel relationship between a pair of counter-rotating pressing areas at their line of tangency, said pressing areas being adapted to exert sufiicient force such that tangles and knots in the filamentary material are thereby substantially destroyed then crimping said material while the ends are still substantially spaced apart to form a web-like bulky mass, then backing up said yarns adjacent said areas to complete crimping of the filaments, setting the acquired crimps thus formed, releasing said resultant crimped material, and cutting the crimped and set filamentary product into staple lengths to form a spinable staple fiber blend of downgraded filamentary material. It is essential that the downgraded material that is utilized to produce the product of this invention by the process thereof, be originally found on creelable pirns or other suitable supply packages. In practice, the mill producing such waste segregates their downgraded material into groupings having a common denier per filament. For example, all 40/ 13; 60/20; 100/34; multifilament nylon yarns are grouped together, giving an average of three denier per filament. Similarly, all yarns such as 140/23; 200/34; 420/68; and 840/140, etc., when grouped together give an average of six denier per filament. Separate ends of such common groupings of filamentary material are then creeled and fed to crimping equipment adaptable to carrying out the process disclosed in our U.S. 'Patent No. 3,164,882, and as hereinafter described. Equipment capable of carrying out such process is available to process filamentary material having a total denier between as high as 100,000 to more than 125,000.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a plan view, partially schematic, of apparatus for carrying out the process of this invention;

FIG. 2 is an enlarged view, partly broken away of a portion of the apparatus shown in FIG. 1;

FIG. 3 is an enlarged view, partly broken away, of another portion of the apparatus shown in FIG. 1;

FIG. 4 is a sectional side elevational view of the apparatus shown in FIG. 1 taken along the lines and in the direction of the arrows IV-IV of FIG. 1; and

FIG. 5 is a view taken along the lines and in the direction of the arrows VV of FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference to the drawings, a creel 10 is provided with a plurality of downgraded filamentary material sup ply packages 11, from which are drawn a plurality of spaced ends 12 of such material, which ends 12 are passed through a guide or eye board arrangement 13 which serves to maintain said separate ends independent of each other and fed in parallel relation when brought into the apparatus hereinafter described. The eye board 13 is mounted on a platform 1'4 of a crimping device 15 such as shown in FIGS. 1 and 4. Said device includes a bed or table 16 supported by a plurality of legs 19'. It Will be noted that the guide or eye board 13 as mounted is slidable on platform 14 so that its position and location may be precisely adjusted to properly guide the yarns through a pin guide member 18 mounted on said platform. Said pin guide member 18 comprises a frame containing a plurality of spaced pin members 18a corresponding to the openings in eye board 13 so as to keep the ends separate and spaced from each other.

Device 15 is provided with a pair of relatively adjustable, vertically disposed, peripherally smooth pressure rollers 19 and 20 which are mounted on shafts 21 and 22, respectively. The roller shafts are rotatably mounted in bearings 23 and 24, respectively, which in turn are secured to the framework of the device 15. Said bearings are constructed so as to be able to resist pressure loading up to at least 3000 lbs. per bearing. Shaft 21 is driven by means of a power unit 25 to a drive means 26, interconnecting pulley 27 fixed to said shaft 21 and a pulley 28 fixed to the shaft of power unit 25. Said power unit 25 drives a gear (not shown) mounted on shaft 21 which in turn drives a gear mounted on shaft 22 and which is meshed therewith so as to simultaneously rotate rollers 19 and 20 in opposite directions.

Said rollers are in tangential relation with each other at their point of contact with the filamentary material as clearly shown in FIG. 4. The rollers are adjustable as hereinbefore described, but are not in actual contact because of the presence of the ends of material 12 during the working of the device as will become apparent hereinafter. It will be noted that relative adjustment of the rollers is accomplished by means of a spring or other suitable tension regulating =frame unit 29, which is provided with a rotatable handle means 30 and a threaded shaft 31 extending through a threaded opening 32 in a bracket 33.

Roller 20 is pressure urged against roller 19 by means of a pressure spring or suitable device 34 which presses against a housing 35. By operating handle 30, the housing 35 and shaft 22 can be moved vertically with respect to the other shaft 21. Said unit 29 is provided in order to permit a slight yielding movement of the roller 20 with respect to roller 19 as the ends pass between them as shown in FIGS. 1 and 4.

Each end 12 after passing through the pin guide member spacing arrangement 18 is directed trough individual slots 36 of a dividing device 37 as shown in FIG. 2. The ends 12 were passed through said slots in parallel and spaced relation through said dividing device 37 which is so made that it is located directly between the forward or entering bight or nip 38 of rollers 19 and 20 as shown in FIGS. 1 and 4. The divider 37 is suitably mounted to the device 15 and includes for purposes of illustration a substantially rectangular framework when viewed from the top, comprising side members 39a and 39, and a pair of front and rear members 40 and 41, one of which 40 is clearly shown in FIG. 2. The rectangularly shaped framework supports a plurality of flat metal strips 42 through which the individual ends 12 pass. Said strips and framework have a tip or reverse apex 43 which extends into the area, nip or bight of the rollers 19 and 20.

The flat strips 42 in addition to the above description are generally V-shaped as more clearly shown in FIGS. 1, 2 and 4 and as stated, the points of the depending strips are aligned and directed toward the tangential line of the rollers 19 and 20 to direct the ends 12 individually in a spaced apart relationship therebetween. It is to be noted that by means of the eye board arrangement 13, guide pins 18a and divider device 37, the ends are maintained spaced apart and parallel with each other before they enter the nip or bight of the rollers 19 and 20. It is to be further noted that these rollers are elongated and of such length as to accommodate the web of parallel adjacent ends 12 as shown in FIG. 1.

Disposed on the other side of rollers 19 and 2.0 is a stuffer box 44 as clearly seen in FIGS. 1 and 4. As the yarns are drawn between the rollers 19 and 20 they enter into the stuffer box 44, where because of its restricted area, the ends are backed up, retained and crimped by the weight and pressure of pivoted or hinged pressure door 45, whereby the yarns accumulate in the stuifer box in such a manner that they remain substantially in a spaced apart relationship to each other and in the form of a folded crimped web or sheet. In lieu of the divider 37 as shown, there may also be used a unit merely having individual plates extending over the lower roller and having one half the shape of the framework and plates shown in FIG. 2. During the operation of the apparatus in accordance with the process of this invention, the ends are passed or brought between the slots 36 and it will be noted that each of the ends will therefore have suflicient room on either side of its longitudinal axis for the component filamentary material to become three-dimensionally splayed or disoriented while passing between the rollers 19 and 20 and into the box 44 with the result that the individual filaments while being crimped form a zigzag pattern relatively of the normal longitudinal axis of the filament, and that also the filaments have sufiicient room to form lateral crimps at different angles and amplitudes with respect to the longitudinal axis of the yarn, all as more clearly shown in US. Patent No. 3,273,220. In other Words, there is a change in direction of the crimp in the filamentary material about the axis of the yarn. This type of crimp forms a product which is more billowy, bulky and lofty. A product made from filamentary material of this type exceeds the bulkiness and loftiness of natural wool. Also in accordance with the process of this invention, the pressure exerted by the rollers 19 and 20 on the ends 12 as they pass therebetween is adjusted so as to be sufficient to substantially destroy any knots and/or tangles which may exist in the downgraded filamentary material. It has been found that in order to satisfactorily so destroy such imperfections, a force of an amount in the range of from about 75 lbs. per lineal inch of the rollers to about 1000 lbs. per lineal inch of the rollers is required. This knot and tangle destroying pressure is important in order that the steps of garnetting and gilling heretofore used in reprocessing downgraded filamentary material may be avoided in accordance with the process of this invention.

After the yarns have passed between the rollers 19 and 20, and have filled up box 44, they press against the walls thereof as a result of the continued increment of ends forced into the box 44 by the rotation of the aforesaid rolls; and as a consequence the ends force the pivotal pressing door 45 to yield against such pressure of the accumulated ends, whereupon the crimped ends pass out of the box 44 onto a table 46, from whence they drop or are passed through a condenser 47 and into a staple cutter 48. The staple product of this invention is then collected in a suitable box 49.

The crimps acquired by the filamentary material may be heat set at any time after they are formed, for example, in the stuffing box, or after cutting into staple lengths, in accordance with conventional heat setting methods. The permanently crimped staple product is thereby produced as a spinnable staple blend of downgraded filamentary material suitable for fabrication.

A supply package of downgraded filamentary material having the following components is prepared:

10 yarns of 70/23 2 yarns of /34 1 yarn of 200/68 1 yarn of 30/10 2 yarns of 40/13 The combined bundle of these yarns represents approximately 1210 denier, with individual filaments being approximately 3 denier. Eighty such supply packages are creeled and introduced into the apparatus hereinbefore described. The bearing pressure of the rolls is adjusted to provide a lineal force of 500 lbs. per lineal inch, and the material is processed as hereinbefore described, with the result that a crimped staple fiber blend suitable for spinning and fabrication is produced.

Depending on the denier and diameter of the individual spaced ends in accordance with the process of this invention, the space between ends across the line of tangency of the pressure rollers may vary from about .016 inch to about .5 inch. By such variations, it is also possible to vary the crimping effects on the filamentary material.

The advantages of the process in accordance with this invention which are obvious herein include the conversion of downgraded yarns having excessive knots, twist, finish, etc. into uniformly crimped and opened filamentary material which when out into staple lengths is suitable for carding and spinning. Moreover, the resultant staple fiber produced is in a three-dimensional high bulk crimped form, which results in a bulkier spun yarn and consequently a fabric with better coverage and less yarn consumption.

These advantages may be contrasted also with the irregular staple product produced as a result of conventional garnetting and tow crimping Where inherently the constituent fibers have greatly varying lengths.

Having thus described our invention we claim:

1. A method of producing three dimensionally crimped staple fiber from waste synethetic filamentary material comprising the steps of:

(1) assembling a plurality of supply packages of waste synthetic filamentary material characterized by knots, excessive twist, excessive finish and the like, the average denier per filament of each package being substantially identical,

(2) continuously feeding a yarn from each supply package into a web comprising such yarns in a spaced apart generally parallel relationship,

(3) continuously guiding said web of yarns into the nip of a pair of counter-rotating rotary pressure members, said yarns being maintained at said nip in said spaced apart and generally parallel relationp,

(4) maintaining sufiicient lineal pressure against said web of yarns at said nip by means of said pressure members that the knots in said yarns are substan tially destroyed,

(5) discharging said yarns from said nip into a common housing still in said web form and spaced apart generally parallel relationship, whereby said yarns are caused to continuously crimp as they are discharged from said nip in such manner that successive portions of each yarn are folded upon the following portion of the respective yarn at an angle in the range of from about 30 to about and said crimps are located in random planes about the axis of the respective yarn,

(6) continuously releasing the resultant crimped web from said housing,

(7) setting the acquired crimp in said web, and

(8) staplizing said Web, whereby there is produced a 7 high bulk three-dimensionally crimped staple fiber suitable for spinning and fabrication.

2. The process of claim 1 wherein the lineal pressure at the nip of said rollers is maintained between about 75 lbs./ inch and about 1,000 lbs./ inch.

3. The process of claim 1 wherein the distance between said yarns just prior to entering said nip is maintained between about 0.016 inch and 0.5 inch.

References Cited UNITED STATES PATENTS 2,715,309 8/1955 Rosenstein et al. 28-72 XR 7/1964 Carruthers 28---72 XR 9/1966 Rosenstein et a1. 28-72 XR OTHER REFERENCES ROBERT R. MACKEY, Primary Examiner.

US Cl. X.R. 

